1. Field of the Invention
The invention relates to a capsular equatorial ring which can be implanted into the opened capsular bag of an eye and, in the implanted state, bears with its outer circumference against the inside of the capsular bag at the equator of the latter and radially stabilizes the capsular bag, the said ring having a substantially cylindrical outer circumference adjoining with a relatively sharp edge the end faces of the ring.
2. Description of the Related Art
If the natural lens of an eye must be surgically removed, for example on account of a pronounced dullness, the capsular bag which receives the natural lens and is opened on the anterior side, facing the iris, for removal of the natural lens, is to be preserved in order to change the anatomical conditions in the eye as little as possible and to facilitate the implantation of an artificial intraocular lens.
However, the removal of the natural lens must be expected to entail more or less extensive damage to muscle of fibre bundles which secure the capsular bag externally in the region of its equator within the eye. In order to avoid the associated deformations of the capsular bag or excessive strain on the muscle fibres or tissue fibres remaining undamaged, it is known to implant in the opened capsular bag a capsular equatorial ring of the type specified at the beginning.
Such stabilizing elements are known, for example, from EP 0 507 292 A1. According to a first embodiment, in this case the capsular equatorial ring may be designed as a closed, foldable ring, with the result that the ring can, in spite of its closed form, be inserted into the capsular bag through relatively small surgical openings on the eye. For a good fit, the size of the capsular equatorial ring should, however, be adapted as precisely as possible to the capsular bag.
According to a second embodiment, the capsular equatorial ring may also be designed according to EP 0 507 292 A1 as an open ring part with ends which can be inserted into each other, in order to permit an adaptation to the equatorial circumference of the respective capsular bag.
It is known from EP 0 478 929 A1 to form at the ends to be connected to each other of an open capsular equatorial ring mating sawtooth profiles, in order to permit a connection which is particularly capable of bearing loads.
According to U.S. Pat. No. 5,628,795, the capsular bag rings are preferably to have a toroidal outside, it also being possible, if appropriate, for a ring form open in the shape of a C to be provided.